Self-sensing Magnetorheological Damper Research Articles

A rotary self-sensing magnetorheological damper based on triboelectric nanogenerator

A rotary self-sensing magnetorheological (MR) damper(RSMRD) based on a triboelectric nanogenerator is proposed in this study, which can provide variable torque and state self-sensing without a power supply. Compared with traditional self-sensing devices, the sensing part of RSMRD has the advantages of small size, no external power supply, and good low-frequency response. The feasibility of the angular velocity self-sensing (AVS) function is verified through theoretical derivation and experimental verification. The experimental results demonstrate a linear relationship between the output voltage generated by the AVS component and the rotational speed of the rotating shaft. Additionally, the torque characteristics of the rotary self-sensing MR damper are tested, revealing a torque generation of approximately 9.26 N ⋅ m at a current of 1.6 A. Furthermore, a fuzzy control algorithm for vehicle braking is proposed, based on the model parameters of RSMRD. The simulink software is used to establish a dynamic model of 1/4 car braking, with an initial braking speed of 15 m s−1. The results indicate that the vehicle comes to a complete stop after 1.64 s, with a braking distance of 10.93 m. Throughout the braking process, the vehicle slip rate remains close to the optimal slip rate of 0.2.

Effects of Winding Cylinder Materials on Dynamic Performances of a New MR Damper

In the semi-active control system based on magnetorheological (MR) damper, the separating arrangement of displacement sensor and MR damper is easy to reduce the reliability and increase system cost. Moreover, the detection accuracy of the sensor is not high due to the external disturbance. Based on this, a new displacement differential self-sensing magnetorheological damper (NDDSMRD) is developed to over these shortcomings. The structure design and working principle of NDDSMRD are expounded. In order to analyze the influence of winding cylinder materials for the developed MR damper on displacement self-sensing and damping characteristics, magnetic field simulations and experiments are conducted to investigate the relationship between the damping magnetic flux and self-sensing magnetic flux densities with two winding cylinders made from different materials. A finite element model was built with ANSYS software and magnetic field simulations in static and harmonic state were presented, respectively. Simulation results show that the damping magnetic flux density generated for winding cylinder made of No.10 steel material surpasses the one made of stainless steel material, and the self-sensing voltages are proportional to the damper displacement though the winding cylinders are different. A dynamic experimental test rig was built up to analyze the dynamic damping performances and self-sensing ability. Experimental results show that the damping force produced by NDDSMRD with No.10 steel winding cylinder is larger than that with stainless steel winding cylinder. The self-sensing voltages are also linear to the damper displacements even though with the different winding cylinders. In addition, the self-sensing voltage generated by the stainless steel prototype is greater than the No.10 steel. Moreover, the self-sensing sensitivity of stainless steel winding cylinder can reach to 59mV/mm, which is 7.4 times greater than that the 8mV/mm for No.10 steel winding cylinder.

A novel velocity self-sensing magnetorheological damper: Design, fabricate, and experimental analysis

This article presents the development of a novel magnetorheological damper with velocity self-sensing capability. The velocity self-sensing mechanism, based on the optical tracking technology and numerical circuit technology, was adopted. The configuration and work principle of the velocity self-sensing magnetorheological damper were presented. The self-sensing circuits, built with optical mouse sensor and microcontrollers, were integrated into the hollow upper lid. The hollow upper lid provides a suitable place for the self-sensing circuits, can be installed and disassembled easily, and can be maintained efficiently. The velocity self-sensing magnetorheological damper prototype with 10 kN capacity was theoretically analyzed, fabricated, and investigated. Finally, the damping performance, self-sensing performance, and self-sensing control capability were tested and analyzed. The results indicated that self-sensing velocity unit has high accurate monitoring capability over a wide range of working conditions. The velocity self-sensing magnetorheological damper–based control system has sufficient ability to control the magnetorheological damper.

Development of a self-sensing magnetorheological damper with magnets in-line coil mechanism

In this paper, a self-sensing magnetorheological (MR) damper is proposed, prototyped and experimental evaluations. This proposed MR damper consists of a conventionally damper part and a self-sensing mechanism through compact structure design. The self-sensing mechanism based on electromagnetic induction is composed of cylindrical permanent magnets and self-sensing coils which move vertically. The mathematical algorithm is put forward to describe the self-sensing capability of the proposed MR damper. Meanwhile, the self-sensing ability and damping performance of the proposed MR damper are tested under different excitation frequencies and displacements. The results show that the proposed self-sensing MR damper has both good self-sensing ability and controllable damping capability.

Adaptive Semiactive Cable Vibration Control: A Frequency Domain Perspective

An adaptive solution to semiactive control of cable vibration is formulated by extending the linear quadratic Gaussian (LQG) control from time domain to frequency domain. Frequency shaping is introduced via the frequency dependent weights in the cost function to address the control effectiveness and robustness. The Hilbert-Huang transform (HHT) technique is further synthesized for online tuning of the controller gain adaptively to track the cable vibration evolution, which also obviates the iterative optimal gain selection for the trade-off between control performance and energy in the conventional time domain LQG (T-LQG) control. The developed adaptive frequency-shaped LQG (AF-LQG) control is realized by collocated self-sensing magnetorheological (MR) dampers considering the nonlinear damper dynamics for force tracking control. Performance of the AF-LQG control is numerically validated on a bridge cable transversely attached with a self-sensing MR damper. The results demonstrate the adaptivity in gain tuning of the AF-LQG control to target for the dominant cable mode for vibration energy dissipation, as well as its enhanced control efficacy over the optimal passive MR damping control and the T-LQG control for different excitation modes and damper locations.

Enhanced damping for bridge cables using a self-sensing MR damper

This paper investigates enhanced damping for protecting bridge stay cables from excessive vibration using a newly developed self-sensing magnetorheological (MR) damper. The semi-active control strategy for effectively operating the self-sensing MR damper is formulated based on the linear-quadratic-Gaussian (LQG) control by further considering a collocated control configuration, limited measurements and nonlinear damper dynamics. Due to its attractive feature of sensing-while-damping, the self-sensing MR damper facilitates the collocated control. On the other hand, only the sensor measurements from the self-sensing device are employed in the feedback control. The nonlinear dynamics of the self-sensing MR damper, represented by a validated Bayesian NARX network technique, are further accommodated in the control formulation to compensate for its nonlinearities. Numerical and experimental investigations are conducted on stay cables equipped with the self-sensing MR damper operated in passive and semi-active control modes. The results verify that the collocated self-sensing MR damper facilitates smart damping for inclined cables employing energy-dissipative LQG control with only force and displacement measurements at the damper. It is also demonstrated that the synthesis of nonlinear damper dynamics in the LQG control enhances damping force tracking efficiently, explores the features of the self-sensing MR damper, and achieves better control performance over the passive MR damping control and the Heaviside step function-based LQG control that ignores the damper dynamics.

Characterization and modeling of a self-sensing MR damper under harmonic loading

A self-sensing magnetorheological (MR) damper with embedded piezoelectric force sensor has recently been devised to facilitate real-time close-looped control of structural vibration in a simple and reliable manner. The development and characterization of the self-sensing MR damper are presented based on experimental work, which demonstrates its reliable force sensing and controllable damping capabilities. With the use of experimental data acquired under harmonic loading, a nonparametric dynamic model is formulated to portray the nonlinear behaviors of the self-sensing MR damper based on NARX modeling and neural network techniques. The Bayesian regularization is adopted in the network training procedure to eschew overfitting problem and enhance generalization. Verification results indicate that the developed NARX network model accurately describes the forward dynamics of the self-sensing MR damper and has superior prediction performance and generalization capability over a Bouc-Wen parametric model.

Experimental Identification of a Self-Sensing Magnetorheological Damper Using Soft Computing

This paper presents the development and application of a soft-computing technique in identification of forward and inverse dynamics of a self-sensing magnetorheological (MR) damper based on experimental measurements. This technique is developed by the synthesis of an NARX (nonlinear autoregressive with exogenous inputs) model structure and neural network within a Bayesian inference framework. The Bayesian inference procedures essentially eschew overfitting that could occur in network learning and improve generalization (prediction) capability by regularizing the complexity of learning. In applying the developed technique to the self-sensing MR damper, the present and past information of its input and output quantities, which contain the physical knowledge of the damper, is used to formulate its nonlinear dynamics. The NARX network architecture is then optimized to enhance modeling effectiveness, efficiency, and robustness. Experimental data of the damper subjected to both harmonic and random excitations are used for model identification and assessment. Assessment results show that the formulated Bayesian NARX network accurately emulates the nonlinear forward dynamics of the self-sensing MR damper. Improved generalization (prediction) capability of the NARX network model by the Bayesian regulation is observed by comparing the modeling results with and without considering regularization. An inverse dynamic model for the self-sensing MR damper is further formulated by the developed technique. The proposed soft-computing technique is viable to formulate dynamic models of the self-sensing MR damper for structural control applications.

Design and Performance Evaluation of a Self-Controlled Magneto-Rheological Damper

Magneto-rheological (MR) dampers are semi-active control devices and use MR fluids. Magneto-rheological dampers have successful applications in mechatronics engineering, civil engineering and numerous areas of engineering. At present, traditional MR damper systems, require an isolated power supply and dynamic sensor, which requires large space. This paper presents the achievability and accuracy of a self-controlled, i.e., self-powered and self-sensing magneto-rheological damper using harvested energy from the vibration and shock environment in which it is deployed. Another important part of this paper is the increased yield stress of the Magneto-rheological Fluids. Magneto-rheological fluids that use replacement of glass beads for Magnetic Particles to surge yield stress is implemented here. Clearly this shows better result on yield stress, viscosity, and settling rate. The permanent magnet generator (PMG) is designed and attached to a MR damper. For evaluating the self-powered MR damper’s vibration mitigating capacity, an Engine Mount System using the MR damper is simulated with the help of ANSYS software. The ideal stiffness of the PMG for the Engine Mount System (EMS) is calculated by numerical study. The vibration mitigating performance of the EMS employing the self-powered & self-sensing MR damper is theoretically calculated and evaluated in the frequency domain.

Novel design of a self powered and self sensing magneto-rheological damper

Magneto-rheological (MR) dampers are semi-active control devices and use MR fluids. Magneto-rheological dampers have successful applications in mechatronics engineering, civil engineering and numerous areas of engineering. At present, traditional MR damper systems, require a isolated power supply and dynamic sensor. This paper presents the achievability and accuracy of a self- powered and self-sensing magneto-rheological damper using harvested energy from the vibration and shock environment in which it is deployed and another important part of this paper is the increased yield stress of the Magneto rheological Fluids. Magneto rheological fluids using replacement of glass beads for Magnetic Particles to surge yield stress is implemented here. Clearly this shows better result on yield stress, viscosity, and settling rate. Also permanent magnet generator (PMG) is designed and attached to a MR damper. For evaluating the self-powered MR damper's vibration mitigating capacity, an Engine Mount System using the MR damper is simulated. The ideal stiffness of the PMG for the Engine Mount System (EMS) is calculated by numerical study. The vibration mitigating performance of the EMS employing the self-powered & self sensing MR damper is theoretically calculated and evaluated in the frequency domain.

A magnetorheological damper with an integrated self-powered displacement sensor

In this paper, aiming at self-powering the integrated relative displacement sensor (IRDS) and the corresponding electronic system of an integrated relative displacement self-sensing magnetorheological (MR) damper (IRDSMRD) based semi-active system, the principle of an MR damper with an integrated self-powered displacement sensor is proposed and realized. The prototype of the MR damper with an integrated self-powered displacement sensor is designed and fabricated. In this MR damper, a coil evenly wound on the piston simultaneously acts as the exciting coil for the MR fluid and the IRDS, while a coil evenly wound on the cylinder simultaneously acts as the induction coil (i.e., pick-up coil) for the IRDS and the pick-up coil for the energy harvesting device. On one hand, both the MR fluid and the IRDS are simultaneously magnetized by a mixed signal, in which the carrier signal for the IRDS and the current for the MR fluid with different frequencies are superposed by a superposition circuit. That is, the exciting coil is frequency division multiplexed. On the other hand, when the exciting coil of the MR damper is energized by the carrier signal for the IRDS and the current for the MR fluid, the induced voltage in the pick-up coil not only can be harvested by the energy harvesting circuit to power the IRDS and the corresponding electronic system of the IRDSMRD, but also can be demodulated to obtain the relative displacement of the piston relative to the cylinder. That is, the induction coil for the IRDS and the pick-up coil for the energy harvesting device are functionally multiplexed. The characteristics of the fabricated MR damper with an integrated self-powered displacement sensor, including the energy harvested by the pick-up coil, the relative displacement sensed by the IRDS, and the controllable damping force, are modeled, analyzed, and tested. The feasibility and capability of the proposed principle are validated theoretically and experimentally.

A self-sensing magnetorheological damper with power generation

Magnetorheological (MR) dampers are promising for semi-active vibration control of various dynamic systems. In the current MR damper systems, a separate power supply and dynamic sensor are required. To enable the MR damper to be self-powered and self-sensing in the future, in this paper we propose and investigate a self-sensing MR damper with power generation, which integrates energy harvesting, dynamic sensing and MR damping technologies into one device. This MR damper has self-contained power generation and velocity sensing capabilities, and is applicable to various dynamic systems. It combines the advantages of energy harvesting—reusing wasted energy, MR damping—controllable damping force, and sensing—providing dynamic information for controlling system dynamics. This multifunctional integration would bring great benefits such as energy saving, size and weight reduction, lower cost, high reliability, and less maintenance for the MR damper systems. In this paper, a prototype of the self-sensing MR damper with power generation was designed, fabricated, and tested. Theoretical analyses and experimental studies on power generation were performed. A velocity-sensing method was proposed and experimentally validated. The magnetic-field interference among three functions was prevented by a combined magnetic-field isolation method. Modeling, analysis, and experimental results on damping forces are also presented.

Pareto Optimization-Based Tradeoff Between the Damping Force and the Sensed Relative Displacement of a Self-sensing Magnetorheological Damper

In order to make the best compromise between the damping force and the linearity of the integrated relative displacement sensor (IRDS) of an integrated relative displacement self-sensing magnetorheological damper (IRDSMRD), a Pareto optimization-based method, which optimizes the key structural parameters by taking the damping force and the linearity of the IRDS of the IRDSMRD as the objective functions, is proposed and realized in this article. The Pareto front, representing the best tradeoff between the damping force and the linearity of the IRDS of the IRDSMRD, is obtained by considering that the maximum magnetomotive force applied to the exciting coil of the IRDSMRD is constant. Three IRDSMRDs with different piston modules, which are determined according to the Pareto optimal solutions, are developed and tested. The research results indicate that every point on the Pareto front is an optimal solution that compromises the damping force and the linearity of the IRDS of the IRDSMRD and the optimal damping force of the IRDSMRD with a certain linearity of the IRDS as well as the optimal linearity of the IRDS with a certain damping force can be determined according to the Pareto front for a specific application.

An integrated relative displacement self-sensing magnetorheological damper: prototypingand testing

In this paper, an integrated relative displacement self-sensing magnetorheological damper(IRDSMRD) and the corresponding electronic system to realize the integrated relativedisplacement sensing and controllable damping, including the relative displacementmodulator/demodulator, circuit for superposing the carrier signal for the integratedrelative displacement sensor (IRDS) on the exciting current from the controllable currentdriver for the controllable damping and controllable current driver are developed andtested. In the developed IRDSMRD, the exciting coil is energized by the currentfrom the controllable current driver, on which the carrier signal for the IRDSis superposed by the superposition circuit. The amplitude modulation of thecarrier signal for the IRDS by the relative displacement between the piston andcylinder of the IRDSMRD and the magnetization of the MR fluid are realizedthrough the frequency division multiplexing of the exciting coil for both the IRDSand the MR damper and the relative displacement is accessed by demodulatingthe induced harmonic voltage from the induction coil of the IRDSMRD by thedemodulator. The characteristics of the developed IRDSMRD, including the linearity,sensitivity and hysteresis error of the IRDS and the controllable damping forceare tested on the established experimental setup based on the MTS 849 shockabsorber test system and the real time simulation system. The testing resultsindicate that the developed IRDSMRD can not only achieve the integration of therelative displacement sensing capability but also possesses good performance of therelative displacement sensing of the IRDS and the large controllable dampingforce range. In addition, the performance of the IRDS will not be affected by theexciting current within a certain range and the damping force will not be degradedby the carrier signal for the IRDS. The realized principle and technology of theIRDSMRD lay a foundation for reducing the commercializing cost of MR dampers.